This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The overall goal of this proposed study is to characterize the role of monocytes as 'Trojan Horse'for viral brain entry in an animal model for acquired immunodeficiency virus syndrome (AIDS). The specific objective is to examine possible altered bone marrow functions and monocyte output during acute infection and how monocytes, once emerged into the peripheral blood pool, migrate onward into the Central Nervous System. Defining the characteristics of newly released monocytes in the peripheral blood pool and their capacity for early brain infiltration could lead to novel drug targeting and treatment options that inhibit acute and chronic neuroinflammation by targeting specific monocyte subsets or their migratory signals.